Accordion / 029 — ニューモフィズム

デザイン見本

Soft UI with Light & Shadow
Elegant Button Integration
Tactile & Realistic Feel

光と影のグラデーションだけで凹凸を表現するニューモフィズム（Neumorphism）を用いた、リアルでエレガントな感触のアコーディオンデザインです。

実装コード

HTML

<div class="container">
    <div class="btn-box">
        <button data-default-text="Neumorphic Soft UI" data-open-text="Close">Neumorphic Soft UI</button>
    </div>
    <div class="more">
        <ul>
            <li>Soft UI with Light & Shadow</li>
            <li>Elegant Button Integration</li>
            <li>Tactile & Realistic Feel</li>
        </ul>
    </div>
</div>

CSS

/* Note: 背景色と合わせるため、親要素のbody等の背景色を #e0e5ec に設定することをお勧めします */

.container {
    margin-bottom: 0;
    max-width: 100%;
    background: #e0e5ec;
    padding: 20px;
    border-radius: 20px;
}

.container .btn-box button {
    width: 100%;
    padding: 18px 24px;
    background: #e0e5ec;
    border: none;
    border-radius: 12px;
    font-size: 15px;
    font-weight: 600;
    color: #6a7b8c;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: left;
    box-shadow: 7px 7px 15px rgba(163, 177, 198, 0.6), -7px -7px 15px rgba(255, 255, 255, 0.8);
    position: relative;
}

.container .btn-box button::after {
    content: '';
    position: absolute;
    right: 24px;
    top: 50%;
    width: 12px;
    height: 12px;
    border-right: 2px solid #6a7b8c;
    border-bottom: 2px solid #6a7b8c;
    transform: translateY(-70%) rotate(45deg);
    transition: transform 0.3s ease;
}

.container:has(.more.appear) .btn-box button::after {
    transform: translateY(-20%) rotate(-135deg);
}

.container .btn-box button:active {
    box-shadow: inset 5px 5px 10px rgba(163, 177, 198, 0.6), inset -5px -5px 10px rgba(255, 255, 255, 0.8);
}

.container .more {
    max-height: 0;
    overflow: hidden;
    transition: all 0.4s cubic-bezier(0.25, 0.8, 0.25, 1);
    background: #e0e5ec;
    border-radius: 12px;
    margin-top: 0;
    opacity: 0;
}

.container .more.appear {
    max-height: 300px;
    margin-top: 16px;
    opacity: 1;
    box-shadow: inset 5px 5px 10px rgba(163, 177, 198, 0.4), inset -5px -5px 10px rgba(255, 255, 255, 0.6);
}

.container .more ul {
    list-style: none;
    padding: 20px 24px;
    margin: 0;
}

.container .more li {
    padding: 10px 0;
    color: #7a8b9c;
    border-bottom: 1px solid rgba(255, 255, 255, 0.5);
    font-size: 14px;
    position: relative;
}

.container .more li::after {
    content: '';
    position: absolute;
    bottom: -1px; left: 0; right: 0;
    height: 1px;
    background: rgba(163, 177, 198, 0.3);
}

.container .more li:last-child,
.container .more li:last-child::after {
    border-bottom: none;
    background: transparent;
}

(function () {
    var container = document.querySelector('.container');
    if (!container) return;
    var button = container.querySelector('.btn-box button');
    var content = container.querySelector('.more');
    
    if (button && content) {
        button.addEventListener('click', function() {
            content.classList.toggle('appear');
            
            if (content.classList.contains('appear')) {
                this.textContent = this.dataset.openText || 'Close';
            } else {
                this.textContent = this.dataset.defaultText;
            }
        });
    }
})();